Author: Adel Berradj
Publisher:
ISBN:
Category :
Languages : fr
Pages : 109
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Book Description
Les applications de sécurité routière sont la principale motivation des réseaux de véhicules, bien que d'autres applications de gestion du trafic routier et de divertissement soient envisagées. La communication par diffusion sur plusieurs sauts est une composante importante de ces applications telles que, la signalisation du danger sur la route où la diffusion sur plusieurs sauts est utilisée pour notifier un accident sur la route, une présence d'animal, un objet qui barre la route, un freinage brusque du véhicule en avant, etc. Comme l'information traitée dans ces applications est très critique et peut avoir un effet sur la vie humaine, la diffusion doit être rapide et fiable. Cependant, la diffusion de messages sur plusieurs sauts a de nombreux défis à relever tels que le problème de tempête de diffusion (à savoir, des retransmissions redondantes, une haute charge du canal, une grande contention sur le canal de communication et ainsi, un taux de perte de paquets élevé) dans le cas d'un réseau dense, et le problème de déconnexion quand le réseau est clairsemé. En plus, les applications de sécurité routière sont à temps critique et la satisfaction de leurs exigences est très difficile, car il y a un compromis entre la fiabilité de la dissémination et le délai de livraison. De nombreux travaux ont été menés ces dernières années et une large gamme de mécanismes ont été proposés. Néanmoins, la plupart d'entre eux souffrent toujours de problèmes de collisions quand le réseau est dense et une latence élevée quand la densité du réseau est faible. Le but de cette thèse est d'étudier les protocoles permettant une livraison fiable et rapide de messages d'alerte, de comprendre leurs limites et de proposer une solution pour la dissémination rapide et fiable de l'information de sécurité dans un réseau de véhicule.
Author: Amira Benaidja
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0
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Book Description
Les réseaux véhiculaires, connus sous le terme VANETs, sont des réseaux impliquant des communications entre deux ou plusieurs véhicules et éventuellement une communication avec des éléments d'infrastructure sur la route. Récemment, le concept de systèmes de transport intelligents (STI) a connu beaucoup d'intérêt. Les STI sont des systèmes utilisant les nouvelles technologies de communication sans fil appliquées au domaine du transport pour améliorer la sécurité routière, la logistique et les services d'information. Des défis majeurs ont besoin cependant d'être abordés pour offrir une communication sur la route sécurisée et fiable dans des environnements anonymes et quelquefois hostiles à la communication. Comme dans tout système de communication, les réseaux véhiculaires doivent opérer en respectant des contraintes en termes de qualité de service. Ces contraintes sont d'autant plus strictes quand il s'agit de fournir des services de sécurité sur la route. Ce projet vise à développer des techniques de communication véhiculaires pour le transfert des informations de manière fiable entre véhicules roulant à grande vitesse tout en contrôlant la surcharge du réseau. Ces techniques visent la prise en compte des contraintes temporelles sur les délais de transfert afin d'envisager leur utilisation dans des applications critiques telle que la sécurité sur la route. Pour ce faire, cette thèse propose d'abord un protocole optimal de dissémination de messages d'urgence pour les VANETs. Il est basé sur une stratégie de diffusion qui exploite les véhicules sur la direction opposée afin d'accélérer la dissémination du message d'urgence tout en réduisant le nombre de transmissions. Ainsi, et dans le but d'assurer une dissémination fiable et à faible surcoût, une technique de retransmission périodique intelligente permettant l'adaptation du protocol proposé à différentes densités du trafic routier est proposée. Dans un second volet, ce projet propose une approche hybride de dissémination de messages d'urgence qui combine alternativement les avantages des deux principales approches de dissémination existantes (Sender-oriented et Receiver-oriented dont notre première proposition fait partie) afin de garantir une transmission fiable des alertes tout en réduisant les délais. Les approches Receiver-Oriented qui sont les plus adaptées pour les applications de sécurité dans les VANETs peuvent minimiser la latence et les limitations des approches Sender-Oriented. Mais, ilsdoivent aussi mieux exploiter les apports des messages hello (beacons) échangés dans la technologie IEEE802.11P. Ainsi, et dans le but de surmonter les limites des approches de retransmissions périodiques et celles de relais- multiples afin d'assurer des échanges fiables de messages de sécurité tout en réduisant la surcharge de la bande passante, nous introduisons un nouveau mécanisme DR/BDR (Designated Relay/Backup Designated Relay). Le BDR, dans ce mécanisme, doit remplacer le DR et assurer sa tâche quand il détecte, à travers les beacons colorés échangés,l'échec de ce dernier dans la dissémination du message d'urgence.
Author: Herbert Brown Ames
Publisher: University of Toronto Press
ISBN: 1442633018
Category : Social Science
Languages : en
Pages : 139
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Book Description
The city below the hill is a detailed investigation of social conditions in a working class quarter of Montreal during the 1890s. Based on a house-to-house survey of the neighbourhood, this study catalogues and analyses the life of working people after the first years of rapid industrialization. Sir Herbert Brown Ames was one of the first to recognize that urbanization was inevitable and to set about improving the quality of city life. In this study, first published in book form in 1897, he moves towards the concept of urban ecology—the city is an organism defined by, and expressing itself in, a myriad of social and economic phenomena. As an organic whole its well-being depends upon the well-being of all its citizens. Within this pioneering work are the seeds of the town planning and social welfare movements that later tried to change the urban landscape. The city below the hill is crammed with facts and statistical analyses of late nineteenth century urban workers. A landmark in the development of urban consciousness in Canada and of sociological research, it is one of the first major efforts to solve problems that are still with us.
Author: Alexander V. Sergienko
Publisher: CRC Press
ISBN: 1420026607
Category : Science
Languages : en
Pages : 248
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Book Description
All current methods of secure communication such as public-key cryptography can eventually be broken by faster computing. At the interface of physics and computer science lies a powerful solution for secure communications: quantum cryptography. Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. This allows for totally secure random key distribution, a central requirement for use of the one-time pad. Since the one-time pad is theoretically proven to be undecipherable, quantum cryptography is the key to perfect secrecy. Quantum Communications and Cryptography is the first comprehensive review of the past, present, and potential developments in this dynamic field. Leading expert contributors from around the world discuss the scientific foundations, experimental and theoretical developments, and cutting-edge technical and engineering advances in quantum communications and cryptography. The book describes the engineering principles and practical implementations in a real-world metropolitan network as well as physical principles and experimental results of such technologies as entanglement swapping and quantum teleportation. It also offers the first detailed treatment of quantum information processing with continuous variables. Technologies include both free-space and fiber-based communications systems along with the necessary protocols and information processing approaches. Bridging the gap between physics and engineering, Quantum Communications and Cryptography supplies a springboard for further developments and breakthroughs in this rapidly growing area.
Author: Jan Camenisch
Publisher: Springer Science & Business Media
ISBN: 3642203175
Category : Business & Economics
Languages : en
Pages : 518
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Book Description
At the end of the PrimeLife EU project, a book will contain the main research results. It will address primarily researchers. In addition to fundamental research it will contain description of best practice solutions.
Author: Syed Rameem Zahra
Publisher: CRC Press
ISBN: 1000286320
Category : Computers
Languages : en
Pages : 239
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Book Description
This book provides a comprehensive study of the security and privacy research advancements in Internet of Things (IoT). The book lays the context for discussion by introducing the vulnerable intrinsic features of IoT. By providing a comprehensive discussion of the vulnerable features, the book highlights the problem areas of IoT related to security and privacy. • Covers all aspects of security • Algorithms, protocols and technologies used in IoT have been explained and the security flaws in them analyzed with solutions • Discusses ways for achieving better access control and trust in the IoT ecosystem • Contributes exhaustive strategic plans to deal with security issues of IoT • Gathers contributions from leading-edge researchers from academia and industry Graduates, researchers, people from the industry and security professionals who want to explore the IoT security field will find this book useful. The book will give an in-depth insight in to what has happened, what new is happening and what opportunities exist in the field.
Author: Chevalier François Le
Publisher: Artech House
ISBN: 9781608071357
Category : Radar
Languages : en
Pages : 422
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Book Description
Author: Jon W. Mark
Publisher:
ISBN:
Category : Computers
Languages : en
Pages : 374
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Book Description
For one-semester senior-level/first-year graduate courses in Wireless Communications. Focusing on the fundamentals of wireless communications and networking, this text gives the reader an overview of the salient features of first and second generation wireless cellular systems, and those perceived for the third generation. It identifies the problems that cause information loss in point-to-point signal transmission through the wireless channel, and discusses techniques suitable for minimizing the information loss. The text covers wireless communications in a cellular setting, treating the ramifications in terms of capacity maximization, support for multi-user transmissions, mobility management to facilitate user roaming, and global information delivery through wireless/wireline interworking.
Author:
Publisher:
ISBN: 9780367802905
Category : TECHNOLOGY
Languages : en
Pages : 445
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Book Description
As Vehicular Networks technology enters a critical phase in its evolution, academic institutions, industry, and governments worldwide are investing significant resources into large-scale deployment of such networks in order to leverage its benefits to communication, road safety, and improved traffic flow. Despite the current proliferation of conferences to address the technical, policy, and economic challenges associated with this exciting new technology, notably absent is a self-contained book that integrates and covers these topics in sufficient detail.Vehicular Networks: Techniques, Standards and Applications examines the latest advances in the evolution of vehicular networks, presenting invaluable state-of-the-art ideas and solutions for professionals and academics at work on numerous international development and deployment projects. A versatile text, it cross-references all key aspects, including medium access, scheduling, mobility, services, market introduction, and standard specifications. This informative guide:Describes the roles of networks operators, car manufacturers, service providers, and governmental authorities in development of vehicular technologyIllustrates the benefits and real-life applications of vehicular networksAnalyzes possible business models for network deploymentExamines potential services and possible deployment architecturesExplores the technical challenges of deployment, including use of MAC protocols, routing, data dissemination, dynamic IP autoconfiguration, mobility management, security, and driver/passenger privacyIllustrative Figures to Clarify Both Basic and Advanced ConceptsUsing simplified language, this book elucidates the distinct behavior and characteristics that disti
Author: Claudio Scardovi
Publisher: Springer
ISBN: 3319669451
Category : Business & Economics
Languages : en
Pages : 242
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Book Description
This book analyzes the set of forces driving the global financial system toward a period of radical transformation and explores the transformational challenges that lie ahead for global and regional or local banks and other financial intermediaries. It is explained how these challenges derive from the newly emerging post-crisis structure of the market and from shadow and digital players across all banking operations. Detailed attention is focused on the impacts of digitalization on the main functions of the financial system, and particularly the banking sector. The author elaborates how an alternative model of banking will enable banks to predict, understand, navigate, and change the external ecosystem in which they compete. The five critical components of this model are data and information mastering; effective use of applied analytics; interconnectivity and “junction playing”; development of new business solutions; and trust and credibility assurance. The analysis is supported by a number of informative case studies. The book will be of interest especially to top and middle managers and employees of banks and financial institutions but also to FinTech players and their advisers and others.
